The FBI is investigating suspected attempts to hack mobile phones used by Democratic Party officials as recently as the past month, four people with direct knowledge of the attack and the investigation told Reuters.

REUTERS

The revelation underscores the widening scope of the U.S. criminal inquiry into cyber attacks on Democratic Party organizations, including the presidential campaign of its candidate, former U.S. Secretary of State Hillary Clinton, as reported by Reuters.

U.S. officials have said they believe those attacks were orchestrated by hackers backed by the Russian government, possibly to disrupt the November 8 election in which Clinton faces Republican Party candidate Donald Trump. Russia has dismissed allegations it was involved in cyber attacks on the organizations.

The more recent attempted phone hacking also appears to have been conducted by Russian-backed hackers, two people with knowledge of the situation said.

FBI agents had approached a small number of Democratic Party officials to discuss concerns their mobile phones may have been compromised by hackers, people involved said. It was not clear how many people were targeted by the hack or whether they included members of Congress, a possibility that could raise additional security concerns for U.S. officials.